But the debate has not been settled definitively and other possibilities, such as underground methane, are still being investigated.

If it was a meteor, it was a mere tiddler by historic standards – as we'll see.

Tsar Bomba

The biggest human-made bang of all time was the explosion in October 1961 of the Tsar Bomba hydrogen bomb. The Soviet-built weapon blew up over the Novaya Zemlya archipelago off the north coast of Russia with a flash of light that was visible 1000 kilometres away. Windows were broken 900 kilometres away, and the mushroom cloud rose 64 kilometres above the ground.

Afterwards, a visitor to the blast site said, "The ground surface of the island has been levelled, swept and licked so that it looks like a skating rink."

The bang could have been even bigger: Tsar Bomba was originally intended to produce a 100-megaton explosion, but was redesigned to reduce the amount of radioactive fallout created. In the event, it may have yielded 57 megatons – which would have made it just under four times as destructive as the Tunguska meteorite.

It seems unlikely that we will ever build a bigger nuclear weapon. Nukes this large are very heavy, release too much fallout and in any case radiate much of their destructive energy into space. Carpet-bombing an area with small bombs does much more damage.

(Image: Russia State)

Krakatoa

One of the most famous – and largest – explosions in recent history was the 1883 eruption of Krakatoa, a volcanic island in the Sunda strait, a narrow strip of sea between the Indonesian islands of Java and Sumatra.

Following months of escalating activity, the volcano erupted in late August. On the most violent day, 27 August, there were four enormous explosions, audible up to 4000 kilometres away. Tens of thousands were killed and many more injured; sailors in the Sunda strait, for example, were deafened by the eruption. Krakatoa itself was virtually destroyed, although later eruptions have created a new island in the same place.

At this point we have to switch scales. Volcanic eruptions are measured on the Volcanic Explosivity Index, which goes from 0 (weakest) to 8 (strongest). Each step on the scale represents a tenfold increase in explosive effect. Krakatoa, rated 6 on the VEI, was equivalent to about 200 megatons of TNT – at least three times as much as Tsar Bomba.

(Image: Everett Collection / Rex Features)

Mount Tambora

Only one explosion in recent history has made it to 7 on the Volcanic Explosivity Index – 10 times bigger than Krakatoa. That was Mount Tambora, on the island of Sumbawa in Indonesia. Tambora started to grumble noticeably in 1812, building up to a cataclysmic eruption in April 1815.

The eruption flung vast amounts of dust and ash into the atmosphere, cooling global temperatures for months afterwards. As a result, the following year – 1816 – became known as the "year without a summer".

Amazing as it now sounds, Tambora was largely overlooked for some 160 years. It was only when scientists, investigating the links between volcanoes and climate, examined ash layers found in Greenland ice cores that the truth was uncovered: no volcanic eruption since 1815 had amounted to more than a damp squib compared with Tambora.

(Image: NASA Earth Observatory)

Lake Taupo

Today, New Zealand's Lake Taupo is a serene sheet of fresh water, beloved of crayfish and hikers alike. Not so 26,500 years ago, when this region was the site of a massive volcanic blast that coated the North Island with ash and rock 200 metres deep. The present-day lake lies in the caldera of the volcano.

The so-called Oruanui eruption was the most recent volcanic event to score the maximum 8 on the VEI – 10 times bigger than Tambora, and 100 times bigger than Krakatoa. Only 47 such "mega-colossal" eruptions are known to have occurred in all of Earth's history.

Taupo is still rumbling away, with more than 20 smaller eruptions known since Oruanui. The image shows Taupo's Mount Ruapehu erupting in June 1996.

Like the Oruanui eruption, it formed an enormous caldera, now partly filled by a lake. The vast amount of dust and ash pumped into the atmosphere is believed to have significantly chilled the world, and may be to blame for a collapse in the human population at the time.

Yellowstone supervolcano

Underneath the beautiful landscape of Yellowstone National Park lies a monster. A plume of hot molten rock that rises from deep within the Earth is believed to cause massive eruptions periodically, some of them big enough to be termed supervolcanoes.

The Yellowstone hotspot has gone off three times in the past few million years. The Huckleberry ridge eruption 2.1 million years ago – which was almost as large as the Toba blast – formed the Island Park caldera. A rather smaller, but nonetheless supervolcanic, eruption formed the Henry's Fork caldera 1.3 million years ago, and the Lava creek eruption 640,000 years ago formed the present-day Yellowstone caldera.

The eruption seems to have started with the volcano spitting out lumps of rock up to 2 metres across, before releasing an enormous pyroclastic flow – a fast-moving gush of hot gas and rock.

Fortunately for us, the La Garita supervolcano is now extinct.

(Image: Kennan Harvey / Getty)

Chicxulub

For bigger bangs than volcanoes can offer, we have to return to cosmic collisions.

Under the town of Chicxulub on Mexico's Yucatán peninsula, buried under 65 million years' worth of sediment, is a crater 180 kilometres across. The image is a computer-generated gravity map of the crater.

The big splash

The most catastrophic blow ever dealt to the Earth probably came when it was very young, some 4.5 billion years ago. At that time, the solar system was newly formed and the Earth's surface still cooling from its initial molten state. Just as things were settling down, along came a second planet, about one-tenth as massive as the Earth.

This body, dubbed Theia, seems to have hit the Earth quite slowly compared with asteroid impacts like Chicxulub, and probably at an oblique angle. But its sheer size made for a truly colossal blow.

Much of the mantle and crust of both planets was blown off into space, while Theia's iron core sank into Earth's. Within a century – the blink of an eye in geological terms – the ejected material had come together to form a new world: our moon.

Bangs to look forward to

Unfortunately for our peace of mind, it's unlikely that Earth-shaking explosions are a thing of the past.

The world's nuclear arsenal includes 23,000 weapons (including the one shown) whose total destructive power would amount to thousands of megatons. The likelihood of these going off has fallen since the end of the cold war, but remains high.

As well as a plethora of "normal" volcanoes, six supervolcanoes have been identified: Taupo, Toba and Yellowstone, plus the Valles caldera in New Mexico, Long Valley in California and the Aira caldera in Kagoshima bay, Japan. We can't reliably predict if or when any of them will explode again. Our luck probably won't hold out forever, but it may be tens or hundreds of thousands of years yet.